Cisco IOS XE Software DNS NAT Protocol Application Layer Gateway Denial of Service Vulnerability

A vulnerability in the DNS application layer gateway ALG functionality that is used by Network Address Translation NAT in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. This vulnerability is due to a logic error that occurs when an...

Researcher discovered vulnerabilities in Layer-2 managed switches

A researcher has found vulnerabilities in network security techniques at the Layer-2 level. The vulnerabilities reside in the fact that the QinQ functionality IEEE 802.1ad standard incorrectly allows VLAN 0 priority tag and 802.2 LLC/SNAP headers can be stacked multiple define VLANs within VLANs....

CVE-2021-27854

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using combinations of VLAN 0 headers, LLC/SNAP headers, and converting frames from Ethernet to Wifi and its reverse...

CVE-2021-27861

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and optionally VLAN0 headers...

CVE-2021-27862

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and Ethernet to Wifi frame conversion and optionally VLAN0 headers...

Code injection

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and optionally VLAN0 headers...

CVE-2021-27862 L2 network filtering bypass using stacked VLAN0 and LLC/SNAP headers with an invalid length during Ethernet to Wifi frame translation

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and Ethernet to Wifi frame conversion and optionally VLAN0 headers...

CVE-2021-27862

CVE-2021-27862 is a Layer 2 network filtering bypass vulnerability where IPv6 RA/RA guard-like filtering can be bypassed via LLC/SNAP headers with invalid length and Ethernet-to-WiFi frame translation (and optionally VLAN0 headers). Public documents confirm exposure across vendor devices (e.g., C...

CVE-2021-27854 L2 network filtering bypass using stacked VLAN0, LLC/SNAP headers, and Ethernet to Wifi frame translation

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using combinations of VLAN 0 headers, LLC/SNAP headers, and converting frames from Ethernet to Wifi and its reverse...

CVE-2021-27853

Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers...

CVE-2021-27853 L2 network filtering can be bypassed using stacked VLAN0 and LLC/SNAP headers

Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers...

Vulnerabilities in Layer 2 Network Security Controls Affecting Cisco Products: September 2022

On September 27, 2022, the following vulnerabilities affecting Cisco products were disclosed by Cert/CC as part of VU855201, titled L2 network security controls can be bypassed using VLAN 0 stacking and/or 802.3 headers "https://kb.cert.org/vuls/id/855201": CVE-2021-27853: Layer 2 network filteri...

PT-2022-4863 · Cisco · Cisco Ios +1

Name of the Vulnerable Software and Affected Versions: No specific software or versions are mentioned in the provided descriptions. Description: The issue is related to the implementation of the Ethernet encapsulation protocol, specifically concerning the combination of headers. This could allow ...

多款Cisco产品安全漏洞

Cisco IOS and others are products of Cisco Corporation.Cisco IOS is a set of operating systems developed for its network devices.Cisco IOS XE Software is an operating system.Cisco Small Business is a switch.Cisco IOS XE Software is an operating system.Cisco Small Business is a switch. Cisco IOS...

多款Cisco产品安全漏洞

Cisco NX-OS Software and others are products of Cisco Corporation.Cisco NX-OS Software is a set of data center-grade operating system software used by switches.Cisco IOS is an operating system developed for its network devices.Cisco IOS XE Software is an operating system.Cisco IOS XE Software is...

PT-2022-9876 · Ieee +1 · 802.2 +3

Name of the Vulnerable Software and Affected Versions: No specific software or versions are mentioned. Description: The issue allows Layer 2 network filtering capabilities, such as IPv6 RA guard, to be bypassed. This can be achieved by using specific combinations of VLAN 0 headers, LLC/SNAP...

PT-2022-9877 · Cisco · Cisco Ios +2

Name of the Vulnerable Software and Affected Versions: No specific software or versions are mentioned in the provided descriptions. Description: The issue allows Layer 2 network filtering capabilities, such as IPv6 RA guard, to be bypassed. This can be achieved by using LLC/SNAP headers with...

PT-2022-9878 · Ieee +1 · 802.2 +3

Name of the Vulnerable Software and Affected Versions: No specific software or versions are mentioned in the provided descriptions. Description: The issue allows Layer 2 network filtering capabilities, such as IPv6 RA guard, to be bypassed. This can be achieved by utilizing LLC/SNAP headers with...

多款Cisco产品安全漏洞

Cisco NX-OS Software and others are products of Cisco Corporation.Cisco NX-OS Software is a set of data center-grade operating system software used by switches.Cisco IOS is an operating system developed for its network devices.Cisco IOS XE Software is an operating system.Cisco IOS XE Software is...

Security Bulletin: Vulnerability in Transport Layer Security Protocol Used in IBM System Networking Ethernet Switches (CVE-2011-3389)

Abstract Earlier versions of the Transport Layer Security TLS protocol are affected by a publicly disclosed vulnerability that could allow information disclosure if an attacker is carrying out a man-in-the-middle attack. Customers can avoid the vulnerability by following workarounds recommended b...